cproj, cprojf, cprojl - project into Riemann Sphere
#include <complex.h>
double complex cproj(double complex z);
float complex cprojf(float complex z);
long double complex cprojl(long double complex z);
These functions project a point in the plane onto the surface of a
Riemann Sphere, the one-point compactification of the complex plane.
Each finite point z
projects to z
itself. Every
complex infinite value is projected to a single infinite value, namely
to positive infinity on the real axis.